This invention relates to a process wherein exhaust steam from a steam turbine operated by geothermal steam is condensed with an aqueous solution containing ferric chelate and the hydrogen sulfide in said geothermal steam is removed.
It is known from U.S. Pat. No. 4,123,506 dated Oct. 31, 1978 and U.S. Pat. No. 4,202,864, dated May 13, 1980 that geothermal steam containing H.sub.2 S can be purified by contacting the steam with a metal compound that forms insoluble metallic sulfides.
It is also known from U.S. Pat. No. 4,196,183, dated Apr. 1, 1980 that geothermal steam containing H.sub.2 S can be purified by added oxygen and passing it through an activated carbon bed.
It is further known from U.S. Pat. No. 4,363,215, dated Dec. 14, 1982 that geothermal steam containing H.sub.2 S can be purified by the reaction of the steam with hydrogen peroxide and a ferrous catalyst.
Various processes for hydrogen sulfide control in geothermal steam are outlined in the U.S. Department of Energy Report #DOE/EV-0068 (March 1980) by F. B. Stephens, et al.
The removal of H.sub.2 S from sour gases and sour water with ferric chelates is shown by U.S. Pat. Nos. 4,009,251, 4,091,073 and 4,076,621.